Collecting ceara rubber (Manihot claziovii Muell) Arg. germplasm

The restricted cultivation of Hevea brasiliensis in the tropical zones due to its agroclimatic preference, necessitates an alternative source of natural rubber for the semi-arid marginal lands. Preliminary studies showed that Manihot glaziovii known as ceara rubber, is a potential plant for such semi-arid marginal lands. The plant was introduced to India in 1902 during the regime of the British. it is well adapted to the dry granitic highlands with scanty rainfall. Under such stress affected conditions, the unselected wild plants yield an appreciable quantity of latex containing more than 80% rubber. Since there is no organised cultivation of M. glaziovii in India, genetic materials are not commonly available. An exploration to the semi-arid hill tracts of Tamil Nadu resulted in the collection of a large semi-wild seedling population. Mature trees were tapped at random and on the basis of the preliminary observations on the bark characteristics, Latex flow pattern and morphological variation in germplasm were also observed.